Patents by Inventor Masaaki Koizuka

Masaaki Koizuka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8497191
    Abstract: A semiconductor device in which selectivity in epitaxial growth is improved. There is provided a semiconductor device comprising a gate electrode formed over an Si substrate, which is a semiconductor substrate, with a gate insulating film therebetween and an insulating layer formed over sides of the gate electrode and containing a halogen element. With this semiconductor device, a silicon nitride film which contains the halogen element is formed over the sides of the gate electrode when an SiGe layer is formed over the Si substrate. Therefore, the SiGe layer epitaxial-grows over the Si substrate with high selectivity. As a result, an OFF-state leakage current which flows between, for example, the gate electrode and source/drain regions is suppressed and a manufacturing process suitable for actual mass production is established.
    Type: Grant
    Filed: October 14, 2008
    Date of Patent: July 30, 2013
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Masahiro Fukuda, Yosuke Shimamune, Masaaki Koizuka, Katsuaki Ookoshi
  • Patent number: 7679147
    Abstract: A semiconductor device in which selectivity in epitaxial growth is improved. There is provided a semiconductor device comprising a gate electrode formed over an Si substrate, which is a semiconductor substrate, with a gate insulating film therebetween and an insulating layer formed over sides of the gate electrode and containing a halogen element. With this semiconductor device, a silicon nitride film which contains the halogen element is formed over the sides of the gate electrode when an SiGe layer is formed over the Si substrate. Therefore, the SiGe layer epitaxial-grows over the Si substrate with high selectivity. As a result, an OFF-state leakage current which flows between, for example, the gate electrode and source/drain regions is suppressed and a manufacturing process suitable for actual mass production is established.
    Type: Grant
    Filed: August 28, 2008
    Date of Patent: March 16, 2010
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Masahiro Fukuda, Yosuke Shimamune, Masaaki Koizuka, Katsuaki Ookoshi
  • Publication number: 20090117715
    Abstract: A semiconductor device in which selectivity in epitaxial growth is improved. There is provided a semiconductor device comprising a gate electrode formed over an Si substrate, which is a semiconductor substrate, with a gate insulating film therebetween and an insulating layer formed over sides of the gate electrode and containing a halogen element. With this semiconductor device, a silicon nitride film which contains the halogen element is formed over the sides of the gate electrode when an SiGe layer is formed over the Si substrate. Therefore, the SiGe layer epitaxial-grows over the Si substrate with high selectivity. As a result, an OFF-state leakage current which flows between, for example, the gate electrode and source/drain regions is suppressed and a manufacturing process suitable for actual mass production is established.
    Type: Application
    Filed: October 14, 2008
    Publication date: May 7, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Masahiro Fukuda, Yosuke Shimamune, Masaaki Koizuka, Katsuaki Ookoshi
  • Publication number: 20090045471
    Abstract: A semiconductor device in which selectivity in epitaxial growth is improved. There is provided a semiconductor device comprising a gate electrode formed over an Si substrate, which is a semiconductor substrate, with a gate insulating film therebetween and an insulating layer formed over sides of the gate electrode and containing a halogen element. With this semiconductor device, a silicon nitride film which contains the halogen element is formed over the sides of the gate electrode when an SiGe layer is formed over the Si substrate. Therefore, the SiGe layer epitaxial-grows over the Si substrate with high selectivity. As a result, an OFF-state leakage current which flows between, for example, the gate electrode and source/drain regions is suppressed and a manufacturing process suitable for actual mass production is established.
    Type: Application
    Filed: August 28, 2008
    Publication date: February 19, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Masahiro Fukuda, Yosuke Shimamune, Masaaki Koizuka, Katsuaki Ookoshi
  • Patent number: 7446394
    Abstract: A semiconductor device in which selectivity in epitaxial growth is improved. There is provided a semiconductor device comprising a gate electrode formed over an Si substrate, which is a semiconductor substrate, with a gate insulating film therebetween and an insulating layer formed over sides of the gate electrode and containing a halogen element. With this semiconductor device, a silicon nitride film which contains the halogen element is formed over the sides of the gate electrode when an SiGe layer is formed over the Si substrate. Therefore, the SiGe layer epitaxial-grows over the Si substrate with high selectivity. As a result, an OFF-state leakage current which flows between, for example, the gate electrode and source/drain regions is suppressed and a manufacturing process suitable for actual mass production is established.
    Type: Grant
    Filed: March 13, 2007
    Date of Patent: November 4, 2008
    Assignee: Fujitsu Limited
    Inventors: Masahiro Fukuda, Yosuke Shimamune, Masaaki Koizuka, Katsuaki Ookoshi
  • Publication number: 20070200203
    Abstract: A semiconductor device in which selectivity in epitaxial growth is improved. There is provided a semiconductor device comprising a gate electrode formed over an Si substrate, which is a semiconductor substrate, with a gate insulating film therebetween and an insulating layer formed over sides of the gate electrode and containing a halogen element. With this semiconductor device, a silicon nitride film which contains the halogen element is formed over the sides of the gate electrode when an SiGe layer is formed over the Si substrate. Therefore, the SiGe layer epitaxial-grows over the Si substrate with high selectivity. As a result, an OFF-state leakage current which flows between, for example, the gate electrode and source/drain regions is suppressed and a manufacturing process suitable for actual mass production is established.
    Type: Application
    Filed: March 13, 2007
    Publication date: August 30, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Masahiro Fukuda, Yosuke Shimamune, Masaaki Koizuka, Katsuaki Ookoshi
  • Patent number: 5641353
    Abstract: The present invention is to manufacture a low hydrogen-concentration silicon crystal having less micro defects caused from oxygen precipitation generated during an annealing process. Particularly, a silicon crystal including hydrogen concentration lower than 0.55.times.10.sup.11 cm.sup.-3, where the hydrogen concentration dependency is small and the micro defect density is less, may be used for a substrate of semiconductor devices. The low hydrogen-concentration silicon substrate is manufactured by measuring the hydrogen concentrations in a silicon crystal and in a hydrogen-doped silicon crystal having a known hydrogen concentration, where both the silicon crystals have been annealed at an equal condition so as to generate thermal donors therein, and by comparing thus measured hydrogen concentrations.
    Type: Grant
    Filed: November 30, 1995
    Date of Patent: June 24, 1997
    Assignee: Fujitsu Limited
    Inventors: Akito Hara, Masaaki Koizuka
  • Patent number: 5505157
    Abstract: The present invention is to manufacture a low hydrogen-concentration silicon crystal having less micro defects caused from oxygen precipitation generated during an annealing process. Particularly, a silicon crystal including hydrogen concentration lower than 0.55.times.10.sup.11 cm.sup.-3, where the hydrogen concentration dependency is small and the micro defect density is less, may be used for a substrate of semiconductor devices. The low hydrogen-concentration silicon substrate is manufactured by measuring the hydrogen concentrations in a silicon crystal and in a hydrogen-doped silicon crystal having a known hydrogen concentration, where both the silicon crystals have been annealed at an equal condition so as to generated thermal donors therein, and by comparing thus measured hydrogen concentrations.
    Type: Grant
    Filed: May 26, 1994
    Date of Patent: April 9, 1996
    Assignee: Fujitsu Limited
    Inventors: Akito Hara, Masaaki Koizuka